if statement is used to write conditional expressions. If the given condition is true then it will execute the statements. Otherwise it will execute optional statements.

syntax:

if<conditon>
{
  -----
  -----
}

While in ladder-if, conditions are evaluated from Top to Bottom. As soon as TRUE expression is found the statement associated with it is executed and rest of the ladder is Bypassed.

syntax:

if(condition-1){
   statement-1
}
else if(condition-2){
    statement-1
}
else{
    statement-2
}

Example of ladder if:

#include <stdio.h>
main()
{
    int a,b,c;
    printf("enter values for a,b,c");
    scanf("%d%d%d",&a,&b,&c);
    if(a>b && a>c)
      printf("%d is big",a);
    else if(b>c)
      printf("%d is big",b);
    else
      printf("%d is big",c);    
}

Parameter Passing is used to provide extra flexibility to a program.

#include<stdio.h>

void f(int n) {
    printf("d",n);
   }

void main() {
    int x = 2;
    f(x);
   }